Process for toasting flaked cereal and the like



April 27 1943.

Original Filed Aug. 2, 1940 T. R. JAMES PROCESS FOR TOASTING FLAKEDCEREAL AND THE LIKE 7 Sheets-Sheet l Ap 22% 1943a T. R. JAMES PROCESSFOR TOASTING FLAKED CEREAL AND THE LIKE Original Filed Aug. 2. 1940 7Sheets-Sheet 2 '7 Sheets-Sheet 3 T. R. JAMES PROCESS FOR TOASTING FLAKEDCEREAL AND THE LIKE Original Filed Aug. 2, 1940 April 27, 1943. v

Aprl 27, 1943. T. R, JAMES 2,317,532

PROCESS FOR TOASTING FLAKED CEREAL AND THE LIKE Original Filed Aug. 2.1940 7 Sheets-Sheet 4 April 27, 1943.

"r R. JAMES PROCESS FQR'TOASTING FLAKED. CEREAL AND THE LIKE Original'Filed Aug. 2, 1940 '7 Sheets-Sheet 5 April 27, 1943;

T. R.,JAMFS PROCESS FOR TOASTING FLAKED CEEAL AND, THE LIKE 55% xo www2@'7 Sheets-Sheet 6 Znveho 2. SWS W April 27, 1943. l T,r R, JAMES2,317,532

A PROCESS E 'OR TOASTING FLAKED CEREAL AND THE LIKE Original Filed Aug.2, 1940 '7 Sheets-Sheet 7 'l 721061121012 ??R Jai/55.615

Patented Apr. 27, 1943 UNITED STATES ATENT DFFICE PROCESS FOR TOASTINGFLAKED CEREAL AND THE LIKE Thomas R. James, Minneapolis, Minn., assignerto General Mills, Inc., a corporation of Dela- Ware (Cl. SSB-430i 4Claims.

An object of this invention is to provide a ready and eicient processfor drying and toasting a cereal of the flaked type.

Cereals of this type on leaving the flaking rolls carry a highpercentage of moistureabout 18% by weight. The process embodying thisinvention serves to remove most of this moisture and to toast the flakesunder controlled conditions.

Another object is the provision of a process for removing much of thedust from the cereal during the drying process.

These and other objects as will hereinafter ap pear are accomplished bythis invention which is fully described in the following specificationand shown in the accompanying drawings in which:

Figure 1 is a side elevation partly in section of the left-hand end ofan oven embodying the invention;

Figure 1gd is a similar view of the right-hand end of the machine;

Fig. 2 is a vertical longitudinal section through the left-hand end ofthe machine;

Fig. 3 is an end elevation of the left-hand or entering end of themachine;

Fig. 4 is an end elevation of the right-hand or discharge end of themachine;

Fig. 5 is a section on the broken line 5-5 of Fig. 2;

Fig. 6 is a vertical section on the line 6--3 of Fig. la;

Fig. 7 is an enlarged section on the line 'l--T of Fig. 2;

Fig. 8 is a partial enlarged detail of the tension springs of Fig. 7;

Figs. 9 and 10 are partial enlarged sections on the lines 9 and l0 ofFig. 7;

Fig. 11 is a partial enlarged section cn the line IIII of Figs. la and12;

Fig. 12? is a partial enlarged detail of the righthand end of the drummounting of Fig. la;

Fig. 13 is a partial vertical section on the line I3-I3 of Fig. l; and

Fig. 14 is a transverse section on the line Ill-I 4 of Fig. 15.

This is a division of my application Serial No. 349,822, filed August 2,1940.

The embodiment illustrated comprises a main frame having side channelsI5 supported on legs I6, I1, I8, which rest upon a door I9.

A rotatable steel drum is made up of two sections 20, 2| securedtogether by meeting ilanges 22 and bolts 23. The section 20 has spiders24, 25 by means of which it is mounted upon a hollow tubular shaft 26While thedrum section 2l is similarly mounted on spiders 2'I, 28 on ahollow tubular shaft 29, the tubular shafts 26 and 29 being aligned andsecured together by an internal sleeve S0. The hollow shaft 26 has astub shaft 3l secured in its left-hand end, as shown in Fig. 2 and thisis journalled in a bearing 32. The hollow shaft 29 similarly has a stubshaft 33 secured in the opposite end and this is journalled in asuitable bearing 311i. This arrangement of shafts with their drumsections mounted thereon by means of spiders provides a very light butrigid arrangement so that there is relatively little deiection in theshafts in spite of their very considerable length. This drum, throughits shaft, is driven by means of a motor i0 (Fig. l) acting through asuitable gear reduction l, a sprocket i2 and chain 43 to a sprocket Aflon stub shaft 3 I The left-hand drum section 20, as shown in Fig. 2, ispartially closed at the entering end by means of a disk having a centralopening 5I. Each of the drum sections is provided with a series oflongitudinal buckets 52, as shown in cross section in Fig. '7, whichserved to pick up the material to be treated and to drop through thedrum as the latter revolves as shown by arrows in Fig. 6, therebybringing it intimately in contact with the moving currents of air asWill later be described. These buckets preferably stop a little short ofthe left-hand end of the drum, as shown in Fig. 2, to accommodate aseries of flights 53. Other series of lights 54, and 5S are locatedbetween these longitudinal buckets to propel the material acted uponfrom entering into the discharge end of the drum, as will presently beexplained. Similarly, the drum section 2l is provided With buckets 09and with flights 6l spaced therebetween, as shown in Figs. 1a and 6, Thedrum section 20 is provided with a series of small drilled holes 52 toprovide egress for the heated air as well as for any ne dust which willbe carried out by the air currents during the drying and toastingprocess.

That portion of the drum section 20 occupied by the hole E2 is inclosedby a stationary housing made up of end walls E5 and side walls 55S.These members are made hollow and are filled with a suitable heatinsulator as shown. `The entering in of the drum is inclosed withsimilarly insulated sections El to provide a passage G9 of the entranceof the hot air. A chute 69 extends diagonally across this space andentering into the drum and this chute is adapted to carry the akedcereal or other material to be treated as by drying and toasting.

Referring to Figs. 1EL and e, the discharge end of the drum is inclosedby the stationary housing 'IB to provide a passage 'II to which thematerial treated is propelled. rIhe walls of the bottom of this passageare inclined at I2 and are provided with an opening '|3, for dischargeof the material into a suitable hopper 'M which guides the material to aconveyor belt or other suitable means for handling the toasted cereal.

A suitable rotatable connection is provided between the drum and thesestationary housings at the points A, B and C of Fig. 1 and D of Fig. le.These connections are all similar and are shown in detail in Figs. '7 to10, inclusive. A description of the connection C will serve for all.

Thus the housing 55 is provided with a stationary ledge 89 havingannular iianges 3|, 32 welded thereto and to the member G so that theledge 83 is concentric with the axis of the drum. A solid bearing ring85 is made up preferably in three sections, as shown in Fig. 7, whichare yieldably secured together by means of bolts 86 passing throughbosses B'I, the ends of the rings being rabbeted at 88 where they passeach other. These sections are urged toward each other by means ofsprings 89 and bolts @il so that the ring 85 closely grips the ledge S3.

Referring to Fig. 10, the stationary member 55 also carries a tube |59in which is located a spring Il which presses the ring 85 against thebearing member 9|. The springs ISI are spaced at intervals about thering.

A bronze bearing ring 5| is secured to annular flange 92 by means of capscrews 93. The nange 92 is secured to the drum by means of rivets. Anoil cup, or the like, 94 is carried by the ring 85 which has an oil hole95 arranged to carry oil to the ring SI. Thus a simple and efficientsliding connection is provided between the drum and the stationarymember E5 which is substantially airtight. There is some slip betweenthe members 89 and 85 and oil from the oil cups working down along theside of the ring S5 sufficiently lubricates these members.

In order to provide for the unequal expansion of the drum and of itssupporting frame, the shaft of the drum is journalled in the bearing 32(Fig. 2) and permits for the expansion of the drum at the right-handend, as shown in Figs. le, 11 and 12. In this the housing 'I9 is movableforward and back with the drum has a lug |05 at each side connected to arod |06 which passes through a spring It?, the latter bearing against abracket |33 on the frame I5. Thus the springs |37 at each side keep thehousing 'IS drawn up against the bronze bearing ring 9|. The housing T6is carried on supports I|2 which bear on rollers IE5 which take abearing on plates H9 on the side frame members I5. The drums are coveredwith suitable insulation I. Screws I3 are adjusted to contact thesupports H2 when the oven is at room temperature.

The method of heating the air for the oven will now be described. Itconsists essentially of two air heaters E and F (Figs. 1 and 1a) whichare disposed beneath the oven. The intake to the oven E consists of apipe I |5 which draws air from the top of the dust chamber 55a andpasses it through a pipe ||6 (Fig. 13) to the intake of a fan II'I(Fig. 1) which delivers through a pipe ||8 to the sapce 5S at the intakeend of the oven. A damper ||9 is provided in the pipe H5 and an airinlet |29 is provided with a damper I2| for introducing room air intothe heater.

This heater is also provided with a suitable gas burner |25 (Fig. 13) bymeans of which a jet of 75 heated air is introduced into the heater, theproducts of combustion mixing with the air and passing through the faninto the space 68 from which it nows into the inlet end of the oven. Itpasses through the holes 62 into the duts collector E35a and backthrough the pipe |I5 to the heater. The dust collector connects througha pipe |26 to a stack, a damper |2'I in this pipe serving to control theoutflow of gases. The heater F is similar to the heater E and has a pipe|28 leading lthereto from the dust chamber 65a. After being heated, thehot air is delivered by a fan |29 to a pipe |39 which forces it into thehousing space 'Il at the delivery end of the oven.

The fan I I1 is designed to deliver approximately three times asA muchair as the fan |29 and the heater E is set to deliver this air at atemperature of approximately 600 F. while the heater F delivers air at atemperature of approximately 750 F` for one type of naked cereal. Bythis arrangement the cereal which, when received from the naking rollscontains about 18% of moisture, is Very rapidly heated, as it ispropelled slowly by the nights 54 and a very large percentage of itsmoisture is quickly removed. 'I'his material delivered by the chute 69is rapidly moved to the nights 54 by nights 53. As it then passes thenights 55 over the holes 62 it loses most of its remaining moisture sothat by the time it reaches the nights 5| it has largely been dried andis ready for toasting. This toasting action is preferably done with airpassing through this portion of the oven at a relatively slow rate butthe cereal itself is moved rapidly during this last portion of theoperation by the nights 6|, the nights 55 giving the material a rate ofnow between that of nights 54 and 6|.

The temperature of the incoming air in the pipe I I5 is indicated by athermometer I3Iand that of the outgoing air by a thermometer I3Ia.Likewise thermometers |32 and |33 indicate the temperatures of the airpassing to and from the heater F. By following these indications and bymanipulating the various controls, the operator is able to maintain thespeed of the drying and toast-ing operations to a very high degree.

As has been indicated before, the nne dust generated in the oven iscarried back and nnds its way through the holes 62 into the dustcollector Where it drops to the bottom and is propelled by means of ascrew |40 driven by sprockets and a chain |4I from a shaft '|42 which inturn is driven by a chain I 43 from a sprocket |44 on the shaft 3|. Thisdust is slowly propelled toward the opening |45 where it drops into asuitable receiver.

Thus it will be seen that I have provided a very simple and efficienttype of oven for drying and toasting naked cereals and the like and onewhich requires a minimum amount of attention to keep it operatingsuccessfully.

While I have shown and described but a single embodiment of myinvention, it is to be understood that it is capable of manymodifications. Changes, therefore, may be made which do not depart fromthe spirit and scope of my invention as disclosed in the appendedclaims.

I claim as my invention:

1. The process of drying and toasting a naked cereal comprisingdirecting the cereal through a rotating drum, passing heated air intothe two ends of the drum, withdrawing air from the middle of the drum,rotating said drum so as to drop the cereal through the moving air, andremoving dust from the middle of the drum.

2. The process of drying and toasting a aked cereal comprising passingthe cereal continuously through a rotating drum, directing heated airinto the two ends of the drum, withdrawing air from the middle of thedrum, rotating said drum so as to drop the cereal through the movingair, and removing dust from the middle of the drum.

3. The process of drying and toasting a flaked cereal comprisingdirecting the cereal through a rotating drum, passing heated air intothe two ends of the drum, withdrawing air from the middle of the drum,and rotating said drum so as to drop the cereal through the moving air,and removing dust from the middle of the drum the air passing throughthe entering end of the drum being hotter than the air passing throughthe delivery end.

4. The process of drying and toasting a naked cereal comprisingdirecting the cereal through a rotating drum, passing heated air intothe two ends of the drum, withdrawing air from the middle of the drum,and rotating said drum so as to drop the cereal through the moving air,and removing dust from the middle of the drum the air passing throughthe entering end of the drum being hotter and moving faster than tha airpassing through the delivery end.

THOMAS R. JAMES.

